Question

The magnification of the image formed by a lens is +1 for the object position at 32cm in front of the lens. Then the power of a lens will be​

Answer 1

The magnification of the image formed by a lens is +1 for the object position at 32 cm in front of the lens.

To find : The power of lens will be....

solution : using formula,

magnification of lens, m = v/u

here object distance, u = -32 cm

⇒+1 = v/-32 cm

⇒v = -32 cm

now find focal length of lens.

using formula, 1/v - 1/u = 1/f

⇒1/-32 - 1/-32 = 1/f

⇒1/-32 + 1/32 = 1/f

⇒0 = 1/f

as you know power of lens, p = 1/f

so, P = 1/f = 0

Therefore the power of lens will be zero.